Amyvid, also known by its generic name florbetapir, is designed to be used in patients undergoing positron-emission tomography scans in order to "light up" areas of the brain that contain beta-amyloid.

Doraiswamy and other researchers working with lead author, Christopher Clark of sponsor Avid Radiopharmaceuticals, used the chemical florbetapir F 18, which binds with beta-amyloid, in conjunction with positron emission tomographic PET imaging.

In the first study, published in this week's Journal of the American Medical Association (JAMA), older people without dementia whose blood showed lower levels of beta-amyloid 42/40 (proteins) had an increased rate of cognitive decline over nine years.